Piston



March 13, 1928.

C. B. TONEY, JR

PISTON Filed Jail. 27. 1927 Patented Mar. 13, 1928.

UNITED STATES PATENT canon.)

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Heroic.

Application filed January 27, 1927. Serial No. 163,910.

My invention is a piston particularly adapted for what are termedmud pumps ing a resilient expansible packin used in well drilling.

An object of in invention is the construction of a piston iaving a resilient packing, such packing being positively forced against the cylinder in which the piston reciprocates by by-passing some of the fluid puinped by the piston.

A particular object of my invention is the construction of a piston for use in a mud pump in pumping a solution of water and clay forminga mud, for use in well drlllmg. The hose or pipe connection leading from the pum has a by-pass which is connected to a hol ow piston rod. The piston is providedwith opposite heads and a resilient packing, such as rubber, between the heads,

.the hollow piston communicating with a stood from the following description and drawings, in which Figure 1 is a side elevation, partly broken therein.

Figure 2 is a longitudinal section through away, of a pump having my piston installed a cylinder, through the piston, and the piston rod.

' Figure 3 is atransverse section through the piston on the line 3-3 of Fig. 2.

In the drawings the pump is designatedgenerally by the numeral 1, having a power end 2, and a pump cylinder3 in which opcrates my piston, designated generally by the numeral 4, theypiston being connected to the hollow piston rod 5. 4 Such rod is operated by the source of power 2 to reciprocate the piston in the usual manner.

The inletto the pump is designated by the numeral 6 and the, outlet by the numeral 7. This outlet is" connected to a pipe 8 or hose which in well drilling leads to a drilling mechanism having a tube for conveying mud to the bottom of the well. A by-pass 'p pipeor hose 9 connects from the pipe 8 to the hollow piston rod. This pipe or hose is flexible so that it may accommodate the reciprocation of the pistonrod.

Referring particularly to Figs. 2 and 3 the piston has front and back heads 10 and 11. The head 10 has a screw threaded connection 12 with the end of the iston rod and 'is held in place by a nut 13. he end of the hollow piston rod is closed by a plug 14.' The inner head 11 fits aganst a shoulder 15 on the piston rod and is preferably a tight pressed fit. Each of the heads has an annular recess 16 in whichis fitted a rubber ring 17. This ring has a series of holes 18 there through, leading to the groove 19, so that such rings may be expanded as hereunder described. The resilient packing rings, preferably made of rubber, are held 1n place by a ring 20 fitting tight on the piston rod.

The main packing of the piston comprises a resilient packing ring 21, preferably formed of ru ber, this being seated on cylindrical walls 22 of each of the piston heads and being confined between the inner walls 23 which converge as they extend radially outwardly from the piston rod. The hollow piston rod has one or more ports 24 leading from such hollow rod to the annular space 25 inside the picking 21.

The manner of operation of my piston is substantially as follows:

The piston is reciprocated in the cylinder in any suitable manner and when it is filled with mud this rod is forced through the discharge pipe 8 and part of it is by-p'assed through the flexible hose 9 to the hollow piston rod and passing thr'ou h the port 24 seals theannula-r space 25, t us forcing the rubber packing 21 tightly against the walls of the cylinder. This forms a seal between the piston andthe cylinder preventing the mud from passing from one side to the other of the piston.

The mud under pressure in the hollow space 25 also forces its way through the openings or apertures 18 into the groove 19 of the resilient packin rings 17' and expands such rings formmg .a tight seal between the piston heads and the connecting rod and thus preventing the mud from working its wa along such rod.. The mud in the space or camber 25 is maintained at a. high pressure, this being substantially equal. to the pressure at which it is-foreed out of the ump. a

It will thus be seen that my piston has an effective seal against the cylinder and also g;

' silient packin expanded resilient packing at the piston rod.

preventin the mud or like fluid being pumped om working its way along the piston rod.

Various changes may be made in theprinciples of my invention without departmg from the spirit thereof, as. set forth in the description, drawings and claims.

, I claim:

' 1. In the art described, the combination of a cylinder, a piston having a resilient packing thereon, a hollow piston rod, there ein a chamber between the packing and the ro ports throu h the rod to said chamber, a discharge pipe operatively connected to the c linder, and means to bypass some of the uid pumped from such discharge pipe to the hollow pistonrod, such fluid expanding the packing against the cylinder.

2. In the art described, a pump having a cylinder with inlet and discharge passages, a piston having a pair of heads with resilient packing therebetween, a hollow iston rod. connected to the heads, there being a chamber between the packing and the rod, with a port in the rod to said chamber, a' pipe connected to the discharge passage, and a exible tubular connection from said pipe to the hollow piston rod to 'b -pass some of the fluid pumped into thecamber to expand the packing.

3. A pump comprising in combination a cylinder having an inlet and a discharge, a piston having a air of heads, a hollow pis vton rod to which said heads are connected, each head having a cylindrical wall, a rering seated on said wall, there being a c amber between the ring and the piston rod, with a port through the rod to said chamber, and means formin a flexible tubular connection from the dlscharge tothe hollow piston to by-pass part of the fluid pumped to the said chamber to expand the packing.

4. A ump, as claimed in claim 3, expansible resi lent packing rings between each head therein, said ring havin 5. A pump comprising in combination a cylinder having aninlet and a discharge, a piston havinga pair of heads secured to a hollow piston rod, the heads having cylindrical walls and inner walls converging radially outwardly from the piston rod, a

resilient packing ring seated on the cylindrical walls and confined between the con- 'vergent walls, there being a chamber between said packing and the piston rod, a port in the rod ,to said chamber; a discharge pipe connected to the discharge, and a flexible bypass pipe connecting said pipe and the hollow piston rod to 'by-pass some of the fluid pumped into the said chamber to expand the said packing.

6. A pump, as claimed in claim 5, each of the heads having an annular recess adjacent the rod, a resilient packing ring therein having a peripheral groove, and a series of holes through the ring to said groove, thereby connecting the chamber to the groove to allow passage of the fluid from the chamber to the oiiahe rings between the head and the piston r 7. A piston having a pair of heads connected to a hollow piston rod, a resilient packing between the heads, there being. a chamber between the packing'and the rod, a port through the rod to the chamber, each of the heads having an annular recess adjacent the rod with a resilient ring fitted aperiphera groove with a series of holes through each ring to the groove in the ring, thereby connecting the groove and the chamber whereby when the chamber is filled with a fluid the fluid fills the grooves and expands the rings against the heads and the rod.

In testimony whereof I have signed my name to this s ecification.

CHARLES ARFIELD TONEY, Jn.

roove to expand each 

